The market for phone cases has continued to grow with the prevalence of high-priced, fragile smart phones. However, most cases are either flimsy, cheap, and offer little or no protection, or they are large, bulky, and mask the aesthetics of the mobile device they are designed to protect. An example of the latter type of case is shown in U.S. Pat. No. 6,646,864 to Richardson. Some of these bulkier cases are designed to be watertight or water resistant up to a certain depth. However, in order to seal the phone or mobile device, they must completely seal it—often significantly increasing the size of the case.
Another feature common among prior art phone cases is a raised protective lip or rim around the periphery of the device face. In other words, the case extends out beyond the face of the device (and any cover over the device face), such as shown in FIG. 1 of Richardson. This “protective rim” serves to protect the face of the device (often glass) from impact should it be dropped. One of the most common failure modes for smart phones and the like is a drop, in which case the glass fascia of the device may crack or shatter. The extended rim is designed to absorb the majority of the impact and protect the screen of the device from damage. Obviously, the larger the rim and the further it extends outward from the device, the more protection it offers. However, the rim obstructs the view of the screen at angles, increases the outside package of the case+device combination, and is generally unappealing.
Another method to protect the device face that is necessary in watertight case models is to cover the face of the device with a generally transparent membrane. This membrane may be a second glass covering or a clear plastic of sufficient thickness to help absorb impacts. The membrane is sealed to the protective rim in some fashion, creating an airtight and watertight cover around the device. In the prior art, the membrane may be held in place through a compression fit, where top and bottom clam shells come together from opposite sides of the membrane. For example, U.S. Pat. No. 8,342,325 to Raynor. In other cases, the membrane may slide into, or otherwise be fixed to the upper clam shell. However, in all cases having such a membrane, a raised protective rim or other feature of the case extends up above the surface of the membrane in order to help retain it and seal it. For example, Raynor provides an example of a much less obtrusive rim, such as in FIG. 1B, but it is still present.